Safety-scaffold



PtentedSept. 14, 1920.

2 SHEETS-SHEET 1.

atto/ammi l F. B. JOHNSTON SAFETY SCAFFOLD.

APPLICATION FILED xunaso. 191e.

www fof@ F. B. JOHNSTON.

SAFETY SCAFFOLD.

APPucATloN r|LED1uNEao,191s.

1, 352,454, Patented Sept. 14, 1920.

2 SHEETS-SHEET 2.

5 nvm/tto@ atto/ama 13 www FRANK B. JOHNSTON, OF NEW YORK, N. Y.,

ASSIGNOR T0 AMERICN SAFETY DEVICE COMPANY, A CORPORATION yOF NEW YORK.

SAFETYSCAFFOLD.

Specification of Letters Patent. Patented Sept. 14, 1920.

Application filed June 30. 1916. Serial No. 106,782.

To all "whom t may concern.'

Be it known that I, FRANK B. JOHNSTON, a citizen of the United States,and resident of New York city, borough of Manhattan, State of New York,have invented certain new and useful Improvements in Safety- Scaffolds,of which the following is a specification.

The present invention relates to improvements in safety scaffolds, andparticularly.

scaffolds as are used in the erection of tall buildings. t

An object of the present invention is to provide in suoli soaffolds, animproved con trolling system by which a length of scaffolding may bemanually raised and lowered by one person, in an expeditious and uniformmanner. Another object is to provide suoli controlling' means which willbe adaptable to different lengths of scaffolds.

With these and other objects in view, my invention is shown in theaccompanying drawings, and will be hereinafter more fully described withreference thereto, and finally pointed out in the claims.

In the accompanyingr drawings,

Figure 1 is a perspective view of a scaffold embodying my improvements,and showing the incompleted wall of a building,

Fig. 2 is a top plan view thereof,

Fig. 3 is a top plan view of a modified form of construction, and

Fig. 4 is a similar view of another modified form of construction.

Similar reference characters indicate corresponding parts throughout theseveral figures of the drawings.

Referring to the drawings, and more particularly to Figs. 1 and 2thereof, scaffolding machines 10, 11 and 12 for supporting,`

and raising and lowering the scaffolds are mounted at suitable intervalsalong the wall of the buildings, upon outriggers 13 in the usual manner.These scaffolding machines each comprise drums 14 and 15 upon which thecables 16 supporting the scaffold platform 17 are wound, these drumsbeing operated by worm gears 18 and 19, propelled by worms 18 and 19 ofthe shaft 20. Clutch devices 21 and 22 prevent rearward movement of thed rums during the raising of the scaffold. These clutch devices be madeinoperative by manually disengaging the y ratchet teeth and turning thepin 23 into the circumferential slot 24.

At the end of the shaft 2O of the machine 10, there is provided a pulleywheel 25 over whichV an endless cable 25 is engaged, which extendsdownwardly to the scaffold platform and in reachof the workmen. There isalso mounted on the shaft 20, a second pulley 26 which is connected toanother pulley 26 of equal size on the drive shaft of the next machine11, by an endless cable 27t Similarly the drive shaft of the machine 11is provided with a second pulley 28 which is connected by an endlesschain 29 to a pulley 30 on the drive shaft of the third machine 12, andso on all of the machines of the scaffold are these cooperativelyconnected. By pulling on the cable 25 it will be seen ally of themachines are correspondingly operated and the scaffold platform isuniformly raised at all points. The main operating pulley need notnecessarily be at the end machine, but may if desired be at anintermediate point.

In Fig. 3 I have shown a slightly modified form of carrying out myinvention. The drive shafts of each machine are provided with worm gears31 which are engaged by worms 32 mounted upon a shaft 33, extendingalong the length of the scaffold. At one end the said shaft is providedwith a pulley 34 over which is engaged an endless cable, which extendsdownwardly to the scaffold platform. By pulling upon this cable all ofthe machines will be simultaneously operated, and the scaffold platformuniformly raised.

In the further modified form of construction illustrated in Fig. 4 thedriving shafts of the machines are extended inwardly into the buildingand are provided on the inner ends with pulleysr35, 36 and 37, connectedby endless cables 38, 39. The shaft of the end machine is provided withan operating pulley 40 over which an endless cable is engaged. This formof construction enables the scaffold to be operated from within thebuilding, and also takes the weight from the outer end of the machines.

I have illustrated preferred and satisfactory forms of my invention, butit is obvious that changes may be made therein within the spirit andscope thereof, as defined in the appended claims.

I claim:

1. In a scaffolding apparatus, an elongated platform, a plurality ofraising and lowering means supporting said platform suspended at aplurality of points, means operatively connecting all of said raisingand lowering means, whereby operation of one of said last named means,simultaneously and equally operates all of said last named means, andmeans operable-from one point for effecting said simultaneous and equaloperation to cause equal movement of said platform at all points in asubstantially level position.

2. In a scaffolding apparatus, an overhead struc-ture, a plurality ofcable Winding machines mounted upon said overhead structure at spacedpoint-s, an elongated platform, cables connected to said respectiveWinding machines and supporting said platform suspended at spaced pointsthereon, and adapted upon operation of said machines to raise and lowersaid platform at said spaced points, means operatively connestingr saidmachines, whereby operation of one of said machines simultaneously andequally operates all of said machines, and means operable from one pointfor effecting said simultaneous and equal operation to cause equalmovement of said platform at all points in a substantially levelposition.

3. In a scaffolding apparatus, an elon gated platform, a pluralityofhoisting units supporting said platform at a plurality of points, and acommon operating means connected to all of said hoisting units andcontrollable from one place of manipulation, whereby a single person maycontrol all of said hoisting units for .simultaneously lifting of saidplatform at said plurality of points.

4. In a scaffolding apparatus, an elongated platform, a plurality ofraising and lowering means supporting said platform, suspended at aplurality of points, each of said means including independent operatingmeans, and common means operatively connecting said independentoperating means, whereby operation of one of said last named meanssimultaneously and equally operates all of said last named means tocause equal movement of said platform at all points in a substantiallylevel position.

ln testimony that I claim the foregoing as my invention, I have signedmy name in presence of two subscribing Witnesses.

FRANK B. JOHNSTON. W'itnesses:

D. Lewis MATTERN, A. BLUM.

